Machine for producing patterns photographically on the surface of copper and like rollers



March 18, 1952 FRANK 2,589,933

MACHINE FOR PRODUCING PATTERNS PHOTOGRAPHICALLY ON THE SURFACE OF COPPER AND LIKE ROLLERS Filed Aug. 4, 1950 2 SHEETS-SHEET 1 March 18, 1952 FRANK 2,589,933

' MACHINE FOR ODUCING PATTERNS PH GRAPHICALLY ON THE S ACE OF COPPER AND L ROLLERS Filed Aug. 4, 1950 2 SHEETS-SHEET 2 N Ev sxx N m mu mun Patented Mar. 18, 1952 MACHINE FOR PRODUCING PATTERNS PHOTOGRAPHICALLY ON THE SUR- FACE OF COPPER AND LIKE ROLLERS Laszlo Frank, Sale, near Manchester, England Application August 4, 1950, Serial No. 177,694 In Great Britain July 18, 1949 1 Claim. 1

This invention relates to the photographic reproduction of patterns or designs upon copper or like printing rollers and is concerned with the means by which the roller with the pattern in firm contact therewith is brought into correct horizontal position for the photographic process to be carried out.

The invention consists in a machine for use in the photographic reproduction of patterns or designs upon printing rollers comprising jacks for supporting at an adjustable height the ends of the mandrel carrying the printing roller, a transparent cover to pass round the printing roller and clamp a positive or negative thereon of the pattern or design to be reproduced photographically upon the printing roller, clamps for holding the ends of the cover beneath the print ing roller, and means for raising the jacks simultaneously to apply resilient pressure to the roller for tensioning the cover.

The invention further comprises a construction of machine in which the jacks comprise rollers to support the printing roller mandrel and allow it to turn freely to prevent uneven tensioning of the cover.

The invention further comprises a construction of machine in which the jacks can be bodily elevated by rack and pinion mechanism operating on the jacks through springs, there being a common shaft for the rack pinions of the two jacks, with a handle or the like for turning the shaft, pawl and ratchet wheel mechanism for holding the shaft in any desired position with the jacks elevated and a release means for the pawl to allow the jacks to fall.

The invention further comprises a construction of machine in which the clamps for holding the two ends of the cover comprise bars upon channel members supported at an adjustable height and at an adjustable distance apart, the cover end passing round the bar and into the channel where it is clamped by a bar inserted over the cover and locked in the channel.

Referring to the accompanying explanatory drawings:

Figure 1 is a side elevation and Figure 2 an end elevation of a machine in which the photographic reproduction of patterns or designs on copper or like printing rollers is effected, constructed and arranged in one convenient form in accordance with this invention.

Figure 3 is a sectional end view on the line 3-3 of Figure 1.

Figure 4 is similar to the upper part of Figure 3 but showing the film tightened around the printing roller.

The machine illustrated has jacks a therein upon which the ends of the mandrel I) through the printing roller 0 are supported. Each jack has rollers 01 therein upon which the mandrel end rests so that the jacks offer a minimum resistance to the printing roller turning.

The film or negative having thereon the pattern or design to be photographed on the printing roller 0 is placed upon such roller and over it is placed a celluloid or transparent cover e. The two ends of the latter are brought down the opposite sides of the printing roller and around bars extending along opposite sides of and beneath the printing roller, the bars being spaced apart less than the diameter of the roller 0 so as to give a large arc of contact between the cover e and the'pattern negative around the roller 0. The bars 1 are carried by channel shaped membars 9 mounted upon adjustable supports it carried by slides 2 adjustable in inverted T slots in parts 9' secured to the machine frame. The slides can be locked in the parts 7' by screws it. Each end of the cover e after passing around the bars j is turned up over the channel member at its open side and is held in each channel by a bar m. The ends of the bars m are locked in the channel members by screws 11.

Each jack a has a screwed stem which threads through a nut 0 formed as a handwheel, which when turned by hand cannot move in an axial direction so that turning the nut raises or lowers the jack a and so the printing roller 0. Each nut o is supported on a column 1) when in its lowest position and is secured against axial movement by attachment to a sleeve q guided in the column 10. A plunger 1' enters the bottom of the sleeve q and at its upper end is pressed upon by a spring s, which at its upper end presses on a disc t bearing against an internal shoulder in the sleeve q.

The plunger T has rack teeth formed thereon at u and these are engaged by a rack pinion 12 upon a shaft w extending along from end to end of the machine, there being two rack pinions on the shaft engaging two racks, one for operating each jack, so that the two jacks are operated simultaneously and to a like extent when the rack pinion shaft is turned by the handle a: secured to the shaft. There is a ratchet wheel 11 secured to the shaft 10, and the wheel is engaged by a spring loaded pawl z. The latter serves to hold the jacks a in any position to which they have been raised by manipulating the handle at. When it is desired to drop the jacks to a lower position, the pawl z is released by depressing the foot pedal 2.

The mode of operating the machine is as follows: the copper or like printing roller is supported in the jacks a and the photographic negative or positive film is placed on the roller. The cover e is placed over the photographic film around the roller 0, and its ends are clamped around the bars 1 and the channel members g. The jacks a are now raised to give a preliminary tightening of the cover e by turning the handwheels 0. When the cover is uniformly tensioned, the handle a: is pulled forward and turns the two rack pinions thereon which raise the plungers r beneath the jacks. This applies lifting pressure through the springs s to the jacks so that-the cover is tensioned to the desired extent.

When the photographic process is completed, the pedal 2 is depressed and releases the pawl 2, so removing upward pressure from the springs s. The jacks can now be lowered by turning the handwheels o. The cover ends are released from the clamping bars m in the channel members, enabling the covers to be removed along with the pattern or design beneath the cover. The printing roller 0 can then be removed from the machine.

As the jacks are raised, the rollers d therein allow the printing roller to turn freely to prevent twisting strains on the cover e.

The loading of the jacks through the springs 's when the handle :0 is operated prevents damage to the cover e during tensioning thereof. 1

Instead of using mechanical means for the final tensioning of the cover e, hydraulic means may be employed, the hydraulic fluid acting simultaneously on the two jacks to give equality of tension.

The pattern negative or positive may be held on the printing roller 0 by mechanical means or by hand during the tightening of the cover e produced by raising the jacks a and forcing the roller with the negative or positive thereon firmly into the fold of the cover e.

By the employment of balls or rollers in the jacks I ensure that any pressure applied between the cover and the negative or positive on the roller during tightening of the latter into the cover, which would tend to turn the negative or positive around the roller, will result in the roller turning without displacing the negative or positive thereon.

What I claim is:

A machine for use in the photographic reproduction of patterns or designs upon printing rollers, comprising jacks for supporting at an adjustable height the ends of the mandrel carrying the printing roller to which the pattern or design is secured, a pair of rollers upon each jack to support the printing roller mandrel between them, springs supporting the jacks, rack and pinion mechanism with a common shaft for the two pinions for operating the jacks simultaneously through said springs, pawl and ratchet wheel mechanism for holding the said common shaft in any desired position, means for releasing the pawl to lower the jacks, a transparent cover to pass round the printing roller and clamp thereon the pattern or design to be reproduced photographically upon the printing roller, and clamps for holding the two ends of the cover beneath the printing roller, said clamps each comprising a bar with rounded operative face to engage the cover, a channel shaped member to the flat face of which the bar is secured, the cover passing round the bar and into the channel of the channel shaped member where it is clamped, means supporting each clamp at an adjustable height, and means allowing the clamps to be adjusted away from and towards each other.

LASZLO' FRANK.

REFERENCES CITED The following references are of record'in the file of this patent: V

UNITED STATES PATENTS Number Name Date 2,170,896 Henderson Aug. 29, 1939 2,338,877 Stead July 26, 1941 2,338,878 Stead July 26, 1941 FOREIGN PATENTS Number Country 'Date 519,760 Great Britain Apr. 4, i940 

